/*
 * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License version 2 only, as
 * published by the Free Software Foundation.
 *
 * This code is distributed in the hope that it will be useful, but WITHOUT
 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
 * version 2 for more details (a copy is included in the LICENSE file that
 * accompanied this code).
 *
 * You should have received a copy of the GNU General Public License version
 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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package com.oracle.svm.core.graal.phases;

import org.graalvm.compiler.graph.Node;
import org.graalvm.compiler.nodes.StructuredGraph;
import org.graalvm.compiler.nodes.java.StoreFieldNode;
import org.graalvm.compiler.phases.Phase;

import com.oracle.svm.core.meta.SharedField;

public class DeadStoreRemovalPhase extends Phase {

    @Override
    protected void run(StructuredGraph graph) {
        for (Node n : graph.getNodes()) {
            if (n instanceof StoreFieldNode) {
                StoreFieldNode node = (StoreFieldNode) n;
                SharedField field = (SharedField) node.field();
                if (!field.isAccessed()) {
                    graph.getDebug().log("Remove StoreFieldNode %s to unused field %s", node, field);
                    graph.removeFixed(node);
                }
            }
        }
    }
}
